Automatic liquid dispensing through the use of dispensing machines is well known. Such machines include water machines which dispense water and for a price determined by the operator of the dispensing machine. In actual operation, a customer might insert coins or currency equaling or exceeding the price of the desired item and then press a selection button or buttons to select the liquid quantity. The liquid dispensing machine dispenses the liquid quantity and returns the customer's change, if any is owed. Such machines are highly advantageous, but suffer from a number of drawbacks. For example, the hydro electric power required to operate each water pump and noise pollution of high number of water pumps operating in one facility for each dispenser is not eco-friendly efficient. Also payment is typically limited to credit card, coin operation, debit card or pre-paid card.
Some examples of various attempts for vending liquids from a bulk source of liquids are described in prior U.S. Pat. No. 7,451,015 by Mazur et al.; U.S. Pat. No. 7,681,605 by Emes et al.; U.S. Pat. No. 5,685,435 by Picioccio et al.; and U.S. Pat. No. 2,021,544 by Crown.
Known prior devices relating to vending of liquids are typically limited to specific types of liquids. In general, only a single tank is provided for each liquid type so that the device is not operable for dispensing when the single tank is being refilled with bulk liquid. Refilling however can be time consuming and awkward for large volumes of bulk liquids in many applications where dispensing of bulk liquids in vending environment is desired. Furthermore, the typical construction of a vending device for a bulk liquid involves a tank supported substantially at ground level requiring additional pumps and consumption of unnecessary power to pump the liquid upwardly to the dispensing nozzle for dispensing to the customer.